Spring boot external application.properties

Question

I am developing a spring boot application

I want to override some properties in src/main/resources/application.properties with an external file (e.g.

Answer 1

Note: The following solution will replace the old application.properties entirely

You can place your application.properties in one of the following locations:

• Under /config sub-directory of the current directory
• The current directory
• A classpath /config package
• The classpath root

And then exclude the default one under resources directory, like:

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering>
            <excludes>
                <exclude>**/application.properties</exclude>
            </excludes>
        </resource>
    </resources>
</build>

Find more details in this link

Answer 2

If you do not want to use any solution from above, you could do the following in the start of your main(String args[]) method (before the usage of SpringApplication.run(MyClass.class, args):

//Specifies a custom location for application.properties file.
System.setProperty("spring.config.location", "target/config/application.properties");

Answer 3

I had the same requirement like yours( war package instead of a fat jar) and I manged to externalize the configuration file: In my main class I made this configuration:

@SpringBootApplication
@PropertySource("file:D:\\Projets\\XXXXX\\Config\\application.properties")
public class WyApplication extends SpringBootServletInitializer {

    public static void main(String[] args) {
        SpringApplication.run(WyApplication.class, args);
    }

}   

Hope this will help you. Good luck.

Answer 4

Notes

1) Tomcat allows you to define context parameters 2) Spring Boot will read the properties defined in Tomcat context parameters as if you are defining them as -Dsomething=some_value

Options

Option 1: Hence a possible way is for you to define spring.config.location at the Tomcat context paramter:

<Context>
    <Parameter name="spring.config.location" value="/path/to/application.properties" />
</Context>

Option 2: define a system property at the Tomcat's setenv.sh file

Dspring.config.location=/path/to/application.properties

Option 3: define an environment variable: SPRING_CONFIG_LOCATION

Answer 5

I always use --spring.config.location= in the command line as specified in the documentation, and you can put various files in this, one with default values and another with the overridden ones.

Edit:
Alternatively, you could also use something like :

@PropertySources({
    @PropertySource("classpath:default.properties")
    , @PropertySource(value = "file:${external.config}", ignoreResourceNotFound = true)
})

and specify a external.config in your application.properties.
This would provide a default path for overridding config, that is still overriddable itself by specifying a --external.config in the command line.
I use this with ${external.config} being defined as a system env variable, but it should work with a application.properties variable too.